Step 1

Bring 2 cups water and rice to a boil in a large saucepan over high heat. Cover, reduce heat to a gentle simmer and cook until the rice is just tender, 12 to 15 minutes.

Step 2

Add stir-fry vegetables to the pot, increase heat to high and bring to a boil. Cook until the vegetables are heated through, stirring occasionally, 2 to 3 minutes. Add tofu and cook until heated through, about 2 minutes. Remove from the heat.

Step 3

Combine miso and the remaining 3 tablespoons water in a small bowl and stir to dissolve. Add the miso mixture, scallions, vinegar and sugar to the soup and stir to combine.